Liposomes
The most important and interesting attribute of phospholipids
is their ability to form special molecular structures called
liposomes. The molecular shape of a phospholipid consists of
a water-loving head and two oil-loving tails.
When placing a large number of these molecules into a limited
space they will arrange themselves spontaneously to match their
heads together and also their tails.
The figure above shows the arrangement of a section of a living
cell membrane which consists largely of phospholipids. As you
can see, the phospholipid molecules have arranged themselves
to form a membrane so that oil droplets cannot penetrate the
cell membrane because they would be repelled by the wall of
hydrophilic heads. In like manner, no water can penetrate the
membrane because the lipophilic tails inside will not allow
passage. The only access through the membrane is by special
protein molecules that are programmed to let only certain chemicals
pass in and out of the cell.
Plant phospholipids are all very similar in structure and
composition. Under certain physical conditions they will spontaneously
form microscopic spheres whose walls are very similar in construction
to the actual cell membrane shown above.
The size of these spheres is very small, in the order of a
nanometer. As illustrated, the spheres are hollow inside and
enclose some of the liquid material in which they were formed
(inclusion). Because of the small size of the phospholipid
molecule and microspheres, they can pass through the epidermis
and act as a carrier for the enclosed substances. It is postulated
that when they reach the outside of a living cell membrane
in the dermis they may become accepted as part of the membrane,
being of the same composition. This process is as shown.
Thus, they are able to carry with them any enclosed substances
into the dermis and to the individual cells.
The ability of phospholipids to act as the carrier mechanism
for delivering active ingredients directly to the cell level
has extensive implications for cosmetics. By themselves they
are absolutely non-toxic and cause no skin irritations, not
even around the eyes. Their danger lies in their ability to
carry toxic or contaminated substances into the cells. The
development of liposome technology offers the potential for
many beneficial cosmetic products. However, the cosmetic developer
has to deal very carefully with the selection of raw materials
and the question of the biological fate of the preparation.
The microspheres themselves are constantly undergoing changes
due to thermal activity during preparation and storage. As
a result, each ingredient of the preparation can end up inside
the microspheres over time.
More than 80 percent of the cosmetic products on the market
contain toxic substances that if used in liposome products
will eventually become part of the inclusion inside liposomes
that, in turn, will get inside your skin cells. Therefore,
beware of products with liposomes that also contain substances
causing adverse effects. As an example, preservatives fall
into this hazardous category since they are all cellular toxins.
It has not been decided by the FDA whether liposome products
with inclusions should be considered a medicine and put under
the scrutiny of medical doctors with the advantage of documenting
and tracking of potential long-term adverse effects. According
to the Cosmetic Handbook, published by the Food and Drug Administration, "Products
that are cosmetics but are also intended to treat or prevent
disease, or affect the structure or functions of the human
body, are considered also drugs and must comply with both the
drug and cosmetic provisions of the law."1 Some combinations
of liposomes and active substances certainly qualify for this
category. The cosmetic industry has no intention of waiting
for a decision before cashing in on the remarkable properties
of liposomes. 2
1 U.S. Department of Health and human Services, Cosmetic Handbook,
U.S. Government Printing Office.
2Nikolaus J. Smeh, M.S. Creating Your Own Cosmetics - Naturally.
Alliance Publishing Company, 1995.
Acne benefits
A recent German study concluded that linoleic acid is one
of the most valuable ingredients in cosmetics.1 This study
found that a shortage of linoleic acid increases acne formation,
and that the water loss from skin is inversely proportional
to the linoleic -acid content of the skin. Another compound
that has been shown to be a deep moisturizer and that contains
the single unsaturated fatty acid, linoleic acid, is vitamin
E linoleate. Therefore, unsaturated fatty acid compounds and
vitamin E linoleate should be a part of every serious moisturizing
skin care product.2
1Lautenschlager, H. M.D., Roedinger J. Md, Ghyczy, M.D., The
Use of Liposomes from Soybean Phospholipids in Cosmetics, SOFW,
issue 14/88, p.531-534.
2Nikolaus J. Smeh, M.S. Creating Your Own Cosmetics - Naturally.
Alliance Publishing Company, 1995.
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